5.10-stable review patch. If anyone has any objections, please let me know.
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From: J. Bruce Fields bfields@redhat.com
[ Upstream commit 70b87f77294d16d3e567056ba4c9ee2b091a5b50 ]
inode_query_iversion() can modify i_version. Depending on the exported filesystem, that may not be safe. For example, if you're re-exporting NFS, NFS stores the server's change attribute in i_version and does not expect it to be modified locally. This has been observed causing unnecessary cache invalidations.
The way a filesystem indicates that it's OK to call inode_query_iverson() is by setting SB_I_VERSION.
So, move the I_VERSION check out of encode_change(), where it's used only in GETATTR responses, to nfsd4_change_attribute(), which is also called for pre- and post- operation attributes.
(Note we could also pull the NFSEXP_V4ROOT case into nfsd4_change_attribute() as well. That would actually be a no-op, since pre/post attrs are only used for metadata-modifying operations, and V4ROOT exports are read-only. But we might make the change in the future just for simplicity.)
Reported-by: Daire Byrne daire@dneg.com Signed-off-by: J. Bruce Fields bfields@redhat.com Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfsd/nfs3xdr.c | 5 ++--- fs/nfsd/nfs4xdr.c | 6 +----- fs/nfsd/nfsfh.h | 14 ++++++++++---- 3 files changed, 13 insertions(+), 12 deletions(-)
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c index 0d75d201db1b3..5956b0317c55e 100644 --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -291,14 +291,13 @@ void fill_post_wcc(struct svc_fh *fhp) printk("nfsd: inode locked twice during operation.\n");
err = fh_getattr(fhp, &fhp->fh_post_attr); - fhp->fh_post_change = nfsd4_change_attribute(&fhp->fh_post_attr, - d_inode(fhp->fh_dentry)); if (err) { fhp->fh_post_saved = false; - /* Grab the ctime anyway - set_change_info might use it */ fhp->fh_post_attr.ctime = d_inode(fhp->fh_dentry)->i_ctime; } else fhp->fh_post_saved = true; + fhp->fh_post_change = nfsd4_change_attribute(&fhp->fh_post_attr, + d_inode(fhp->fh_dentry)); }
/* diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 315be1c1ab85c..bdcfb5f7021da 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2426,12 +2426,8 @@ static __be32 *encode_change(__be32 *p, struct kstat *stat, struct inode *inode, if (exp->ex_flags & NFSEXP_V4ROOT) { *p++ = cpu_to_be32(convert_to_wallclock(exp->cd->flush_time)); *p++ = 0; - } else if (IS_I_VERSION(inode)) { + } else p = xdr_encode_hyper(p, nfsd4_change_attribute(stat, inode)); - } else { - *p++ = cpu_to_be32(stat->ctime.tv_sec); - *p++ = cpu_to_be32(stat->ctime.tv_nsec); - } return p; }
diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h index 56cfbc3615618..39d764b129fa3 100644 --- a/fs/nfsd/nfsfh.h +++ b/fs/nfsd/nfsfh.h @@ -261,10 +261,16 @@ static inline u64 nfsd4_change_attribute(struct kstat *stat, { u64 chattr;
- chattr = stat->ctime.tv_sec; - chattr <<= 30; - chattr += stat->ctime.tv_nsec; - chattr += inode_query_iversion(inode); + if (IS_I_VERSION(inode)) { + chattr = stat->ctime.tv_sec; + chattr <<= 30; + chattr += stat->ctime.tv_nsec; + chattr += inode_query_iversion(inode); + } else { + chattr = stat->ctime.tv_sec; + chattr <<= 32; + chattr += stat->ctime.tv_nsec; + } return chattr; }